Research has suggested that antioxidants may help protect brain cells from Alzheimer’s disease, but the results of various studies appear to contradict each other. Antioxidants, such as vitamin E, occur naturally in a variety of fruits, vegetables, grains, legumes, and nuts. They are believed to fight disease by protecting the body's cells from damage. Now, research published in the June 26, 2002 issue of the Journal of the American Medical Association (JAMA) suggests that eating foods rich in vitamin E may reduce your risk of developing Alzheimer’s disease.

About the study

Researchers from Chicago’s Rush-Presbyterian-St. Luke’s Medical Center analyzed data on 815 men and women age 65 or older in the Chicago Health and Aging Project. These people all lived on the south side of Chicago and were free of any form of dementia—including Alzheimer’s disease—when they entered the study between 1993 and 1997.

Upon entering the study, participants underwent medical and mental status examinations and answered questions about medical history and lifestyle habits. Between one and two years later, they completed dietary questionnaires.

After an average of nearly four years of follow-up, researchers compared the antioxidant intake (which includes vitamin E) of those who developed Alzheimer’s disease with those who did not.

The findings

People with the highest intakes of vitamin E were 70% less likely to develop Alzheimer’s disease compared with their counterparts who had the lowest intakes. Of note is that this was only true among people without the APOE gene mutation that causes a genetic predisposition for the disease. Of interest is that taking vitamin E supplements did not seem to affect the risk of Alzheimer’s disease.

In calculating these statistics the researchers accounted for the following factors that affect the risk of Alzheimer’s disease: age, sex, education, race, and APOE4 gene mutation.

Although these results are interesting, there are limitations to this study. Dietary intake of antioxidants was only assessed once, so these measurements may not accurately reflect intake over time. Because Alzheimer’s disease progresses slowly, small changes in cognitive ability that may be present long before diagnosis might affect dietary habits and reporting of dietary intakes. In addition, the dietary assessment was conducted about one to two years after participants entered the study, leaving open the possibility that disease had already begun to develop in some. Finally, this study relied on participants to accurately recall and estimate their intake of various types of foods—a method that may not provide completely accurate assessment of antioxidant intake.

How does this affect you?

The findings of this study suggest that making vitamin E-rich foods a part of your diet may reduce your risk of Alzheimer’s disease. Remember, this study found that foods containing vitamin E, rather than vitamin E supplements, were associated with a lower risk of Alzheimer’s disease.

Regardless of Alzheimer’s disease risk, vitamin E and other antioxidants are part of a balanced diet. Antioxidants are believed to help ward off a number of diseases, including cancer. And there’s certainly no down side to eating some of the following vitamin-E rich foods every day:

  • Grains
  • Nuts
  • Milk
  • Egg yolk

Note: In the same issue of JAMA , another study reported that both vitamin E and vitamin C intake from foods were associated with a lower risk of Alzheimer’s disease. See: “Vitamins C and E may help reduce risk of Alzheimer’s disease.” How is it that this other study found an association between vitamin C and Alzheimer’s, as well? This is yet another indication that science is an ever-evolving process and that it may take years to learn the entire “truth.”